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^ No. 37-1919.

Britieb lengincenuo Stan^arb6 Hs^ociaticn.

(Incorporated 1918). Formed in 1901 as The En'gineerinq Staxdards Cojijiittkk

BY

The Institution of Civil Engineers.

The Institution of Mechanical Engineers.

The Institdtion of Naval Architects.

The Iron and Steel Institute.

The Institution of Electrical Enuinekbs.

BRITISH^ '^'^ STANDARD SPECIFICATION

FOR ,

ELECTRICITY METERS

(REVISED JANUARY. 1919)

LONDON :

PUBUSHKD FOB THE Aksociatioit BY CROSBY LOOKWOOD * SON,

7, Statiokers' Hall Codbt, Lcdo \tb Hill, E.G. 4; and 5, Bkoadway, Wkstminhtee, B.W. 1,

AffD TO BB PCliCHASEO FUOM ANT B0OK8ELXEB, OB OIKECT FBOM THE OfFICES QV THE ASaOCIATION,

28, VicTOKiA Street, Westmiksteb, S.W.I.

January, 1919.

No. 37-1919.

British lEuoincccing Stau^ar^6 B660dation,

(Incorporated 1918). Formed in 1901 as The Exginhekixg Staxdauus Committkk

BY

Thk Institution of Civil Engineers.

Thk Institution of Mechanical Engineers.

The Institution of Naval Architects.

The Iron and Steel Institute.

The Institution of Electrical Engineers.

BRITISH STANDARD SPECIFICATION

FOR

ELECTRICITY METERS

(REVISED JANUARY. 1919.)

LONDON :

Plblishkd KOtt THK ASSOCIATION Bv CROSBY LOCKWOOD & SON,

7, Stationeus' Hali, Couut, Ludgate Hili,, E.G. -1, and 5, Buoadway, Wksiminstku, S.W. 1,

AM) lO UK I'lHCIIAHKD KKOM ANY B00K8KU.KK, Oil Dt UKCT FROM TH K OKFICKS OK T» K ASSOl 1 ATIOM, 28, VlCTOIilA Stkeet, Wkstminsteu, S.W.I.

January, Jt>19.

No. 37—1019.

CONTENTS.

List of Members of Main Committee

List of Members of Sectional Electrical C.'oniniillee

l^ist of Members of Sub-Committee on Electrical Accessories

Preface to First Edition

Preface to First Revision

Preface to Second Revision ...

PAGE

4 5 5 7 7 8

STANDARDS AND DEFINITIONS.

I	British Standards of Electrical Quantities	9
2	Standard 'J'emperature ...	9
3	Indication of Meter	9
4	Circuit	9
5	Main Circuit	9
6	Meter Current Circuit ...	... 9
7	Pressure Circuit ...	9
8	Meter Pressure Circuit ...	10
9	Marked Current ...	10
ID	Marked Pressure...	10
II	Full Load ...	10
12	Rotor	10
'3	Register ...	10
14	Meter	10
15	Switchboard Meter	10

SPECIFICATION : TABLE OF CLAUSES.

GENERAL CLAUSES.

16 17

iS

19 20 21 2 2 23 24

25 26

27 28 29 30 31 32 33 34

General Construction		10
Case
Windows ...
Finish of Case ...
Terminal Compartnicnt ...
Terminals ...
Disconnecting Device for the	Pressure Circuit
Sealing		12
Levelling ...		12
Diagram of Connections		1 2
Construction of Circuits...		12
External Resistances for Pressure Circuit	I 2
Insulation... ... .. ,		1 '^
Rate of Loss of Energy
Direction of Rotation ...		M
Labels		14
Size in Ami)ercs ...		16
Registering Mechanism ...		16
Minimum Running Current		• 17

No. 37—1919.

PAGE

35. Limits of Error ... ... ... ... ... ... 17

36. Variation of Pressure ... ... ... ... ... 17

37. Variation of Air Temperature ... ... ... ... 18

38. Variation due to heating by Main Current ... ... 18

39. Excess Current ... ... ... ... ... ... 18

40. Excess Pressure ... ... ... ... ... ..• 18

4T. Non-registration with Pressure alone ... ... ..- 18

42. Sealing by Manufacturer .. ... ... ... 18

43 Comparison with sealed pattern ... ... .. 19

44. Latent Defects ... ... ... ... ... ... 19

45. Impaired Accuracy ... ... ... ... ... 19

46. Independent Tests ... ... ... ... ..• 19

SECTIONAL CLAUSES FOR DIRECT CURRENT METERS

47. Identification of Termmals ... ... ... ... 19

48. Speed of Rotation ... ... ... ... ... 20

49. Internal Shunts ... ... ... ... .-• 20

5c. Diagram of Connections ... ... ... ... 20

51. Accuracy of Three-wire Meters on Unbalanced Loads 20

52. External Shunts ... ... ... ... ... ... 20

SECTIONAL CLAUSES FOR ALTERNATING CURRENT METERS.

53. Speed of Rotation ... ... .. ... ••• 21

54. Diagram of Connections ... ... ... ••• 21

55. Variation of Frequency ... ... ... .•• • -• 22

56. Variation of Power Factor ... ... • ... 22

57. Correct Registration of Unbalanced Loads ... ... 23

APPENDICES.

I. Precautions necessary in the Erection of Meters ... 24

II. Notes on the Testing of Meters ... 26

III. Illustrations of typical arrangements of Meter Registers 28

No. 37—1919.

( 4 )

BRITISH ENGINEERING STANDARDS ASSOCIATION.

MAIN COMMITTEE. I SI|{ AHCHIBAI.U DKNNY, HAKT. {Choirmov).

SIK MAUKK'K 1 Tl'/MAURIC'K, C.M.c (Vicc-Cluiinnan).

SIK ROHKU'r ELLIOTT-COOPEK, K.C.B. SIR WILLIAM MATTHEWS, K.C.M.(4.

SIR DOUGLAS FOX

MR. AI.KXANDER ROSS

I)H. \V. C. UNWIN

MR. 11. A. IVATT

JIR. MICHAEL LONGRn)(:iE

1)K. WILLIAM H. MAW

MR. G. AINSWOKTH

DR. ARTHUR COOPER

MR. ILLTYD WILLIAMS

SIR THOMAS KELL, K.B.K. SIR WILLIAM SMITH, C.R.

SIR .lOllN S.NELI

COL. R. E. CROMPTON, C.B.

MR. C. P. SPARKS

MR. V. R. DAVKNPORT

MR. V. W. OILBERTSON

HON. SIR CHARLES PARSONS, K.C.B. SIR ROBERT HADFIELD, BART. ... SIR RICHARD GLAZEBROOK, C.B.

Nominated bv the lustitution of Civil Engineers.

Nominated 1)3' the Institution of ^Mechanical Eii"ineers.

Nominar.ed by the Iron and Steel Institute.

Nominated by the Institution of Naval Architects.

Nominated by the Institution of Electrical Engineers.

Co-ojited by tlie nominated Memhi'rs to iei>iesent the Federation of IJvitish Industiies.

Co-opted by the nominated Members.

UK.

.1. 11. T. TUDSBEBY (Hoti. SccrcUirii).

MR. V. LK MAisTRE (Sccirtarii). MR. CHARLES DRESSER {Assistant Secri'Utrii). Jilt. p. (JOOD (Electrical Assistant Sccrctar;/).

t Succeeded the lute SIR JOHN WOLFE BARRV, K.c.i;., K.l.runrv, IHIS.

No. 37—1919.

( 5 )

BRITISH ENGINEERING STANDARDS ASSOCIATION.

The following are lists ol Members of the Sectional Electrical Committee and of the Sub-Committee on Electrical Accessories which was entrusted with the revision ot the following Specification : —

SECTIONAL ELECTRICAL COMMITTEE

WHICH IS ALSO THE BRITISH NATIONAL COMMITTEE

OF THE

INTERNATIONAL ELECTROTECHNICAL COMMISSION.

Chuiriiian, SIR JOHN SNELL [representing the t'rown Agents for the Colonies). Vice-Chairmen, *Sir Richard Glazebrook, C.B. (representing the Natiunai Physical

Lahoratory) ; INIr. Charles P. Sparks. Representing the Adniirdlty, |Mr. C. H. "Wordingham, C.B.E. RepresentiTig the War Office, Major G. L. Hall, R.E. Representing the India Office, Mr. Maurice G. Simpson. Representing the Home Office, Mr. G. Scott Ram. Representing the General Post Office, Sir W. Slingo. Representing the Office of Works, Mr. H. A. McFerran, O.B.E. Nominated by the Institution of Electrical Engineers, Mf . F. Gill ; Mr. J. S.

Highfield ; Ish: Roger T. Sinith ; Mr. W. B. Woodhouse. Nominated hq the British Electrical and Allied Manufacturers' Association,

Mr. D. N". Dunlop ; Jlr. A. R. Everest ; Mr. A. D. Williamson ; Mr. A. P. Wood. Representing the Cable 3Iakcrs' Association, Mr. L. B. Atkinson. Nominated by the Electrical Contractors' Association {Incorporated), Mr. W.

R. Rawlings. Nomiiuited by the Incorporated Association of Electrical Poiver Companies, Mr.

E. T. Ruthven Murray. Nominated by the Incorporated Municipal Electrical Association, i\lr. J. H.

Bowden;"Mr. R. A. Chattock. Nominated by the London County Council, Mr. A. L. C. Fell. Nominated by the Tramways and Light Railways Association, **Mr. S. Sellon. Col. R. E. B. Crompton, C.B. ; Sir John Gavev, C.B. ; Mr. R. D. T. Heap ; Mr.

Walter Judd ; Professor T. Mather ; Mr. "C. H. Merz ; Mr. H. W. Miller ;

tMr. P. F. Rowell; Dr. A. Russell; Capt. H. R. Sankey, C.B., R.E. (ret.) ;

Mr. Alexander Siemens ; Mr. A. P. Trotter.

SUB-COMMITTEE ON ELECTRICAL ACCESSORIES.

Chairman, MR. C. H. WORDIN(;HA.M, C.B.E. (representing the Admiralty).

Representing the War Office, Mr. (i. H. Roberts, C.B.E.

Representing the Home Office, Jlr. G. Scott Ram.

Rep7'esenting the Crown Agents for the Colonies, Mr. A. H. Preece.

Representing the National Physical Laboratory, Sir Richard Glazebrook, C.B.

Nomiiuited bif the British Electrical and Allied Alanu.facturers' Association,

Mr. H. H. Berry ; Mr. F. M. Chapman ; Mr. F. H. Xalder. Nomiiuited liy the Electrical Contractors' Association (Incor/iorated),

Mr. W. R. Kawliiigs. Nominated by the Incoi'poi-ated Association of Electrical Power Companies.

Mr. W. B. Woodhouse. Nominated bii the Incorporated Municipal Electrical Association, Mr. A. C. Cramb ;

Mr. ]•:. E. Hoadley. Brig.-Gen. Sir Capel Holden, K.C.B., R.A. ; Prof. A. S. Barnes; Mr. S. Evershed ;

Mr. J. S. Highfield; Mr. H. W. Miller; Mr. Thomas L. Miller; Mr. S. G.

Castle Russell ; Mr. A. Lester Taylor.

The Sub-Committee has been assisted in the prejia ration of this Revised Sjiccitication by Mr. J. W. Beauchamp, representing the I.M.E.A., Mr. F. A. Neild and Mr. R. H. Schotield, representing the B.E.A.M.A., and by Mr. C. C. Paterson aiul Mr. S. W. Melsom, repi esenting the Director of the National Physical Laboratory.

• PreRident. Britisli Nutidual Oomuiittee.

+ Hon. Sec, Dntish National Comaiittfe.

t Also nominated l)j' tho liistitiui<ni of Kloctriciil Knirincers.

*• Since deceased.

No. 37—1919.

( 7 )

PREFACE TO FIRST EDITION.

The Sub-Committee on Electrical Plant Accessories was appointed at a Meeting of the Sectional Committee on Electrical Plant (Sir William H. Preece, K.C B., Chairman) held on January 15th, 1903, which appointment was confirmed by the Main Committee on December 8th, 1904.

The Meter Manufacturers accepted the invitation of the Committee to give evidence on the question of Electrical Supply Meters, and on January 7th, 1907, the Sub-Committee sat at the Institution of Civil Engineers to hear this evidence, and most careful consideration has been given to the views expressed by the Manufacturers on this occasion. Information has also been gathered from a large number of Central Station Engineers with reference to the question of accuracy, and the Sub-Committee are much indebted for the very full and careful attention given to their enquiries. The Sub-Committee has had the advantage of the assistance and co-operation of Mr. C. A. Baker, representing the London County Council, in drawing up this Specification. Finally, the Sub-Committee desire to place on record their appreciation of the valuable services rendered by Mr. S. Evershed and Mr. J. Rennie in the difficult task of drafting this Specification, which, if generally adopted, cannot fail to be of great assistance to both User and Manufacturer.

This Report was adopted by the Sectional Committee on Electrical Plant at their Meeting held on July i8th, 1907.

This Report was adopted by the Main Committee at their Meeting held on July 22nd 1907.

C. H. WORDINGHAM,

Chairman of the Sub- Commit tee on

Electrical Accessories.

PREFACE TO FIRST REVISION.

The First Edition uf this Specification referred only ti; Consumers' Meters of sizes up to 100 amperes. When the Revision was undertaken, it was found necessary considerably to e.xtend the scope of the Specification in consecjuence of the large increase in size of individual installations arising from the extension of the use of electrical energy, supplied from central stations, which has taken place since the original publication.

Reriuirements for Meters up to the laigest sizes in use as wt-ll as for three-wire and three-phase Meters, have therefore been added. The (juestion of including the Electrolytic type of Meter has been very carefully considered, but it has not been found desirable to do so at present.

NO. 37-1919.

( 8 )

The Specification is intended to apply to the purchase of new Nfeters, governing their sale liy the Manufacturer to the Purcliaserjand it has no direct bearing on nny (juestion which may arise between the Supply Undertakers and their Consumers in connection with such of the Meters as are employed to register energy supplied from l\iblic Supply mains. The ret|uirements have, however, been so drawn up that Meters conforming to them may reasonably be expected to fulfil the conditions imposed by the Board of Trade on Meters used in connection with Public Sujjply Undertakings, and to satisfy Inspectors under the Electric Lighting Acts during a considerable period afier the Meters have been put into service.

This Report was adopted by the Sectional Electrical Committee at their Meeting held on July i6th, IQ15.

This Report was approved by the Main Committee at their Meeting held on July 22nd, 1915.

C. H. WORDINGHAM,

Chair nuin of Siih-Connnitlee on

Electrical Accessories.

PREFACE TO SECOND REVISION.

During the lir.sl revision of this Specification considerable extensions were made to the original Specification issued in 1907, but certain of the clauses in the revised Specification were found to present difficulty, ami it became necessary again to revise the Speci- fication.

Careful consideration has been given to the comments from the various Associations represented on the Committee, and it i.^ believed that the present Specification forms a satisfactory basis for a contract for the purchase of new meters. It must be emphasised that the Specification has no direct bearing on any ([uestion which may arise between supply undertakers and their consumers in connection with such meters as are employed to register energy supplied from public supply meters, this being a matter for the authority constituted under tlie Electric Lighting Acts.

The Committee recognise that while alternating current meters can be obtained having considerably greater accuracies than those specified, direct current meters cannot be expected, in the present state of knowledge, to have very much greater degrees of accuracy than those specified ; since it seemed illogical to recjuire smaller error in one class than in the other it was decided not to discriminate between them.

This Report was adopted by the Sectional Electrical Com- mittee at theii meeting held on loth July, 19 18.

This Report was approved on behalf of the Main Committee on 30th December, 1918.

C. H. WORDINGHAM.

Chairman of Suh-Coniiiiitlee on

Electric a I . A cccssoi ies .

No. 37—1919.

( 9 )

Note. — The Association desires lo call attention to the fact that this Specification is intended to inchide the technical pj'ovisions necessary for the supply oj the article herein referred to, but does not purport to comprise all the neces- sary precisions of a Contract.

BRITISH

STANDARD SPECIFICATION

FOR

ELECTRICITY METERS.

STANDARDS AND DEFINITIONS.

British Standards of Electrical Quantities. -iQ

1. The British Standards for electrical measurement shall be the Legal Standards in the custody of the Board of Trade, and all electrical quantities referred to in this specification shall be measured in terms of these Standards by means of apparatus which

is in agreement with such Standards at the time of use. 15

Standard Temperature.

2. The Standard Temperature for the purposes of this specification shall be 15° C. unless otherwise marked on the meter.

Indication of Meter.

3. Meters shall register in terms of the legal unit of electrical 20 energy defined as one thousand watt-hours.

Circuit.

4. The term ''Circuit" denotes terminals, connecting wires, joints, coils and all other conductors forming a path for an electric current.

Main Circuit.

5. The term " Main Circuit " denotes that circuit which carries the whole current of the supply of which the meter registers the energy.

Meter Current Circuit.

6. The term "Meter Current Circuit" denotes that portion of the main circuit l)etween the terminals of the meter which is con- tained within the meter case.

Pressure Circuit.

7. The term "Pressure Circuit" denotes that circuit which is traversed by a current proportional to the pressure of supply.

25

30

No. 37—1919.

( TO )

Meter Pressure Circuit.

8. 'I'he term " Meter Pressure Circuit " denotes that portion of the pressure circuit between the pressure terminals of the meter which is contained within the meter case.

Marked Current. 5

9. Tlie term " Marked Current " denotes the current in amj)eres marked on the name plate of the meter.

Marked Pressure.

10. The term " Marked Pressure " denotes the pressure in volts marked on the name plate of the meter. 10

Full Load.

11. The " Full Load " of the meter or of each element, if the meter has more than one element, is the marked current at the marked pressure and at unity power factor.

Rotor. 15

12. The term " Rotor " denotes that portion of the motor which forms the prime movement of the meter.

Register.

13. The term "Register" denotes the circular scales and pointers, or the figure openings and figure wheels, as the case may 20 be, from which are read the figures that permit evaluation of the supply to the consumer.

Meter.

a. The term " Meter " includes also such auxiliary appliances as resistances, shunts, current and pressure transformers external to the meter in Clauses 15, 34 to 41, 43 to 46, 50, 51, 54 to 57, and the requirements of these clauses apply when all such auxiliary appliances are operating in connection with the meter of which they form part.

Switchboard Meter. 30

15. The term "Switchboard Meter" denotes a meter fitted with back connections.

SPECIFICATION.

GENERAL CLAUSES.

25

35

General Construction.

16. The construction of the meter (sn; Clause 14) shall he mechanically sound and suitable for its purpose, and .shall be such as to give reasonafjle assurance of permanence in all mechanical electrical and magnetic adjustments and shall not be seriously affected by external magnetic fields. 40

No. 37—1919.

( ri )

Case.

17. The parts of the meter within the case shall be carried on a substantial stiff framework forming, if desired, part of the case. The framework shall not be liable to distortion by changes of temperature, presence of moisture or other cause. They shall be 5 completely enclosed in a substantial dust-tight metal case, the front and sides of which may be glazed. The case shall be of sufficient strength to afford adequate protection to the working parts against mechanical injury with reasonable usage, and capable of being sealed

in such a manner that access to the working parts and the electric or lo magnetic adjustments of the meter can only be obtained by breaking the seals.

Care shall be taken to ensure that the mechanism as well as the interior of the case are free from dust or other extraneous matter immediately prior to sealing. 15

IVlnclows.

18. One or more substantially glazed dust-tight windows shall be provided in the front of the case in such a manner as to give a clear view of the register, and also of those working parts the observation of which is necessary for rapid testing of the meter. It 20 shall be impossible to remove the glass without breaking the seals of the case or breaking the glass itself.

Finish of Case.

19. The case of the meter, together with any framework, shall

be protected on the outside and inside from corrosion and de- 25 terioration by an efficient coating of paint, enamel, or other suitable material not liable to be damaged by ordinary handling, nor injuriously affected by the action of moisture or by exposure to air under normal conditions of use.

Terminal Compartment. 30

20. The terminals of the meter itself, unless of the switch- board type, shall be enclosed by a separate cover suitable for sealing or contained in an external compartment of the case.

Terminals.

21. All meters of sizes above loo amperes shall be provided 35 with soldering sockets, except where provision is made for coupling with strip or bar connections.

Disconnecting Device for the Pressure Circuit.

22. The pressure circuit shall be connected to the supply side

of the main circuit, and a disconnecting device shall be provided in 40 the terminal compartment to enable the pressure circuit to he entirely disconnected from the main circuit, in order that it may be

No. 37—1919.

( ^^- )

.supplied with current from a separate source fur purposes of testing. The disconnecting device is not necessary where separate terminals are provided for the pressure circuit.

Sealing.

23. The meter, unless of the switchboard type having 5 external connections, shall be provided with separate facilities enabling the purchaser to .seal independently the terminal com- [)artment and the meter case. Facilities may also be provided for independent sealing by the manufacturer (See Clause 42).

lievelling. 10

24. Every meter, the accuracy of which is affected by small changes in level, shall be provided with means of ascertaining without breaking the seals that it is correctly levelled.

Diagram of Connections.

26. A meter belonging to any one of the classes defined in 15 Clauses 50 and 54 shall have a diagram firmly attached to the inside of its terminal cover or, in the absence of a terminal cover, to some other convenient part of the meter visible from the exterior. Such diagram shall show the connections and give the particulars required in Clauses 50 and 54. 20

Construction of Circuits.

26. The circuits of the meter shall be capable of carrying full load continuously without injury to any part of the meter, without any permanent change in its accuracy, and without the temperature

of any accessible part of the case exceeding 10° C. above the 25 temperature of the surrounding air, except when a shunt is employed in a separate compartment forming an integral part of the meter, when the temperature of any accessible part of the case of such compartment shall not exceed 30° C. above the temperature of the surrounding air. 30

External Resistances for Pressure Circuit.

27. Resistances for use in the pressure circuit of the meter and not enclosed in the meter case shall comply with the following requirements : —

(a) Every external resistance shall be completely enclosed 35 in a strong metal or other firc-resisling case.

{/?) Every external resistance shall be so constructed that when the marked pressure is applied to the meter and resistance combined, and is maintained continuously, no injury shall be done to any part of the resistance, and the temperature of ?inv 40 accessible part of the case shall not exceed that of the sur- rounding atmosphere by more than 30* C.

No. 37—1919.

( 13 )

(c) Every external resistance shall have the following par- ticulars indelibly marked on a label permanently fixed to the case : —

(i.) The name of the manufacturer of the meter with which the resistance is used. ^

(ii.) The serial number of the meter with which the resistance is used.

(iii.) The pressure for which the meter and resistance combined are intended.

(iv.) The value of the resistance at the temperature 10 marked on the meter label in accordance with Clause 37.

Insulation.

28. The meter shall comply with the following requirements as regards insulation : —

(a) The insulation resistance between all the electric 15 circuits of the meter coupled together, and the containing case, or other metal not intended to be insulated when the meter is in use, shall be not less than 5 megohms.

{Z)) The insulation resistance between the main circuit and the pressure circuit, if any, shall be not less than 2 megohms. 20

(c) The insulating material between all the electric circuits and the containing case, or other metal not intended to be insulated when the meter is in use, shall withstand, for one minute, an alternating pressure equal to twice the pressure of the circuit for which the meter is intended, with a minimum of 1,000 volts. 25 All the electric circuits .shall be coupled together before applying the high pressure. The insulation resistance shall be measured with a pressure of

not less than 200 volts nor more than 500 volts (direct), applied

for a sufficient time for the reading of the insulation indicator to 30

become practically steady.

The requirements of (a) and (c) shall apply to all auxiliary

apparatus, other than pressure and current transformers*, used with

the meter.

Rate of Lobs of Energy. 35

29. The rate of loss of energy in the pressure circuit at marked pressure shall not exceed the values given in the following table : —

,. . Marked Pressures M^t^'-- up to 250 Volts.

1

Marked Pressures above 250 Volts.

Direct 5 watts. Current.

Alternating 2 watts. Current.

2 watts per 100 volts.

1 watt per 100 volts.

40

* For the high pres<;ure tests for pressure and current irans formers, sff British Stam lard Specification for Transformers for meters and other instruments, (Report No. 81) when such is issued. ^'^

No. 37-1919.

( M )

The rate of loss of energy in the meter current circuit for all meters having a marked current not exceeding 50 amperes shall not exceed ten watts ; with the further restriction that the pressure drop shall not exceed two volts.

When the meter has more than one clement the above reijuire- ments shall apply to each element independently.

The pressure drop in external shunts for meters of more than 100 amperes shall be in accordance with Clause 52(1?).

This clause shall not apply to Switchboard Meters.

Direction of Rotation.

30. The forward direction of rotation of the rotor, if any, shall be clearly indicated.

Labels,

31. The meter shall bear a label or labels on the front of the case, effectually secured against removal, and indelibly and distinctly marked with the following particulars : —

(a) Country of origin.

(/') Name of the manufacturer of the meter.

(c) Serial number.

(d) Type mark.

(e) The kind of current and system of distribution.

For example : — " Direct current." " Alternating current." " 3-phase 3-wire." " 3-phase 4-wire."

(/) The maximum current for which the meter is intended, marked on the label as shown in the following table : — ■

Type of Meter.		Method of Marking.		Example.
Two-wire	Full load current through the main circuit.	(I	100 am)ieres."
'j'hree-wire, for direct or single phase alternating current.	2	X the full load current through either of the main circuits.	•'2	■■; 100am])eres.''
Three- or four-wire, two-phase.	2	X the full load current through either of the main circuits.	"2	■•: lOOamperes."
Three- or four-wire, three-phase.	3	y the full load current through either of the main circuits.	•'3	■ 100 amperes."

10

15

20

25

30

35

40

No. 37—1919.

( 15 )

(ir) The pressure of the circuit for which the meter is intended, marked en the label as shown in the following table : —

Type of Meter.

I'wo-wire

Three-wire, for direct or single phase alternatins^ current.

Method of Marking.

The pressure of the cir- cuit to which the meter is to be connected.

2 X the pressure between neutral and outer.

Three-wire, two-phase \ 2 x the pressure between

phase and neutral.

Three - wire, phase.

three-

Four-wire, two-phase

3 X the pressure between phases.

2 X the phase pressure

Four-wire, three-phase I 3 x the pressure between I phases and neutral.

Example.

" 100 volts."

" 2 X 230 volts."

" 3 X 400 volts."

" 2 X 230 volts." " 3 X 230 volts."

(A) The frequency of the circuit in periods per second.

(/) The number of revolutions of the rotor, if any, corre- sponding to one kilowatt-hour This shall be designated as " Revs, per kwh."

(J) The information under Clause 37 if required.

{k) If an external resistance is required in the pressure circuit an indication to that effect shall appear on the label.

(/) The ratio of the potential transformer or transformers. This shall be expressed as a fraction in which the denominator shall be the potential on the pressure circuit of the meter itself thus: 6600/110.

(w) The ratio of the current transformer or transformers. This shall l)e expressed as a fraction, in which the denominator shall be the current through the .series coils of the meter itself, corresponding with the marked current in the primary of the transformer, thus: 1000/5.

(«) If a purchaser's ownership label is required it shall be circular i| inch (35 mm.) diameter, and secured firmly to the case by one rivet.

10

15

20

25

30

35

No. 37—1919.

( '6 )

Size in Amperes.

32. The following shall be the standard sizes of meters {sec Clau.se 14) : — 2"5, 5, 10, 20, 40, 50, 100, 150, 200, 300, 400, 500, 600, Soo, T,ooo, 1,500, 2,000, 3,000, 4,000 and 5,000 amperes.

Registering Mechanism. (This clause does not ajiply to electrolytic meters).

33. The registering mechanism* of the meter shall be either of the pointer type or of the counter type, and shall comply with the following requirements : —

{a) In the pointer type the pointers shall indicate on cir- cular scales, each divided into ten equal divisions, and the radius of the scales and pointers shall be not less than o"28 inch (7" 11 mm.).

{/>) In the counter type, all the figures visible within the register, except the first, t shall spring quickh' into position : the first figure may move continuously. In the case of ([uickly moving figures each opening shall be sufiiciently large to permit clear observation of the figures.

{c) There shall be not less than 5 indices which may be circular scales and/or openings. For figures moving con- tinuously, the openings shall be large enough to permit of two consecutive figures being identified at the same time, but a suitable device shall be used to prevent the figures 9 and o from being seen simultaneously. Those indices which indicate lower values than one kw-h. per division shall be made distinctive from the other indices.

{d) The circular scales and/or the figure openings shall conform with the requirements of the following table : —

Class.	Size. Full load in Kilowatts.	Constants for the Oiiening-s or for one Division of the Circular Scales.
I.	Up to 1-25	100, 10, 1. 1 10, I'lOO.
11.	Above 1-25
	and up to 125	1,000, 100, 10, 1, 1 10.
111.	Above 12-5
	and up to 125	10,000, 1.000, 100, 10, 1.
IV.	Above 125
	and up to 1250	100,000, 10,000, 1,000, 100, 10.
V.	.\bove 1250	In multiples of the above.

10

15

20

25

30

35

* Where meters are rccjuire<l to register accurate!) in the reverse directinn this requirement should he specified. •

T The "first" fitjure means the fij^ure having the lowest significance 40

in the register.

No. 37—1919.

( T7 )

The terms in which the record is made by the register or dial shall be clearly marked as " kilowatt-hours."

In the pointer type of register each circular scale shall be marked to indicate the number of kilowatt-hours represented by one division of the scale. 5

In the counter type, one of the openings shall be marked clearly to indicate the value of the indication in that opening.

No other marking of any kind shall be made on the dial plate.

Minimum Running Current.

34. \Mien a current equal to one-hundredth of the marked 10 current of the meter {see Clause 14) (or when this is less than one- twentieth of an ampere then one-twentieth of an ampere) traverses its main circuit the rotor shall start and continue running steadily, the pressure circuit, if any, being energised at the marked pressure in phase with the current in the main circuit. 15

Limits of Error.

35. The error of the meter {see Clause 14) at the standard or marked temperature, pressure, frequency and at unity power factor shall not exceed the following values : —

Permissible Limit of Error.

Load.

Meters without external shunts or transformers.

I'ull load to one-fifth lull load (inclusive) ...

h'rom one-fifth to one- tenth full load

At one-twentieth load ...

full

Per cent.

from true reading, -h or - 2

2-5

•1-5

Meters with external shunts or transformers.

Per cent.

from true reading.

4- or -

2-5

5-0

20

25

30

When current or ])otential transformers or shunts are employed the accuracy specified al)ove shall be obtained with combined calibration.

If auxiliary apparatus is to be connected to the Iransfoimer t)r shuni the meter should be caliluaied with all such apparatus connected.

Variation of Pressure.

36. If the meter {see Clause 14) has a pressure circuit, a variation of 5 percent, above or below the marked pressure at any load from full to one-tenth shall not cause a change in the rale of registration in re'^pect of such \ariation of more than one per cent.

35

No. 37 — 1919.

( i8 )

Variation of Air Temperature.

37. If the rale of registration of the meter (see Clause 14) changes more than o'l per cent, for a change of air temperature of 1° C, the meter shall have information regarding the temperature co-efficient marked upon the label in the following manner : — 5

" Olihrated at.......' C. Temp. Coeff. + (or - ) . ...% per ° C."

Variation due to Heating by Main Current.

38. The change in the rale of registration of the meter (see Clause 14) from the time the marked current is switched on to the main circuit to the time at which the rate of registration becomes 10 constant at that current shall not e.xceed two per cent. ; and the total error in the rate of registration shall not e.xceed the limits allowed

in Clause 35. When testing for compliance with this clause. the marked pressure shall have been continuously applied to the pressure circuit, if any, for a period of not less than six hours immediately 15 before the test, and no current in excess of one-quarter of the marked current shall pass through the main circuit during that period. In the case of alternating current meters the current sliall be in phase with the pressure.

Excess Current. 20

39. The meter (see Clause 14) shall not be injured and its accuracy shall not be permanently impaired by a current 25 percent, in excess of its marked current maintained for a period of one hour, or by the passage of a current in the main circuit not exceeding 30 times the marked current of the meter for a period not exceeding 25 half a second, the rotor, if any, being free to rotate, and the pressure circuit being energised at marked pressure.

Excess Pressure.

iO. The meter (see Clause 14) shall not be injured and its accuracy shall not be permanently impaired by the application of a 30 pressure 15 per cent, above the marked pressure for a period of one liour.

Non-Registration with Pressure alone.

a. Every meter (see Clause 14) having a pressure circuit shall not register with its main circuit open when the pressure circuit alone 35 is acting, either when marked pressure is applied or when this [iressure is increased to 10 per cent. ai)Ove the marked pressure.

Sealing by Manufacturer.

42. One or more of the sealing places on the case may be sealed by the manufacturer before the meter is delivered to the 40 purchaser (or his representative) and, in the event of these seals being broken or removed at any time after delivery, the manufac- turer shall no longer be under any liability as regards the accuracy of the meter.

15

No. 37—1919.

( 19 )

Comparison with Sealed Pattern.

53. Every meter {see Clause 14) purporting to be of a type

which has been approved and sealed under the Electric Lighting

Acts, in addition to complying with this specification, shall be in

conformity with the sealed pattern of that type deposited at the Board 5

of Trade Electrical Standards Laboratory, and the purchaser (or his

representative) may require a specimen meter to be submitted to an

inspector appointed under the Electric Lighting Acts for examination

in this respect.

Latent Defects. 10

ii. If at any time within three years after the date of delivery any defect in material or workmanship shall become apparent in the meter {see Clause 14) the purchaser (or his representative) may return it to the manufacturer, who shall thereupon make good the defect at his own expense.

Impaired Accuracy.

i5. If at any time within one year after the date of delivery the meter {see Clause 14) shall be found to be registering with an error in excess of the limits prescribed by this Specification and shall not have been subjected to unreasonable usage,* the purchaser (or 20 his representative) may return the meter to the manufacturer who shall thereupon at his own expense adjust it to register within the prescribed limits.

Independent Tests.

46. In the event of any difference between the purchaser (or his representative) and the manufacturer as to the compliance of the meter {see Clause 14) with this specification, either party shall have the right to have it tested by an independent authority to be mutually agreed upon by the parties, or failing agreement, by the National Physical Laboratory, and all the expenses attendant upon such independent testing shall be borne by the party adjudged to be in the wrong.

[If there is any intention on the part of the purchaser or the manufacturer to have any or all meters, under a contract, tested by an in<lepen(ient authority before acceptance, such arrangement should form part of the 35 contract.]

25

30

40

SECTIONAL CLAUSES.

DIRECT CURRENT METERS. Identification of Terminals.

47. The terminals shall be clearly and indelibly marked so as to mdicate the proper direction of the current through the meter. The left hand or bottom terminal, as seen from the frf)ni of the instrument, shall be the positive one.

* Unreasonable usage shall imply, amongst other things, mechanical damage, over-running of coils, storage or use in an uncluly damp or corrosive atmosphere. 45

No. 37—1919.

20

( -'o )

Speed of Rotation.

48. The speed of the rotor shall not exceed loo revolutions per minute at full load.

Internal Shunts.

49. If a shunt is used with a meter the nature of the connec- 5 lions and the resistance of all contacts shall be sufficiently constant

to prevent the meter error being altered.

Diagram of Connections.

50. A diagram in accordance with Clause 25 shall be attached

to every meter (see Clause 14) with a pressure circuit, and to every 10 iwo-wire meter without a pressure circuit intended for currents ex- ceeding 100 amperes.

The diagram for any meter with an external shunt shall show the minimum permissible distance between the shunt and the meter. This minimum distance shall be such that the accuracy of the meter 15 shall not be affected by the magnetic field produced by the current in the shunt and in the conductors carrying the main current.

The diagram for any meter which carries more than 100 amperes through its current circuits shall contain such directions for the correct disposition of the conductors carrying the current to and from the meter, that those errors may be avoided which result from the differences in the magnetic fields produced by placing such conductors in other than their correct positions.

Accuracy of Three-vfire Meters on Unbalanced Loads.

51. When the marked current is flowing in one of the two 25 current circuits of the meter [see Clause 14) and half the marked current flowing in the other circuit, at the marked pressure, the rate

of registration of a meter which purports to be a 3-wire meter shall not change more than i per cent, compared with an equivalent balanced load. 30

External Shunts.

52. If a shunt is neither enclosed in the same case as the meter nor structurally a part of the meter it shall comply with the following refjuirements : —

(a) The shunt shall have the following particulars indelibly 35 marked either on it 01 on a label permanently fixed to it.

(i.) The name of the manufacturer of the meter with which it is to be used.

(ii.) The serial number of the meter with which it is to be used. '^^

(iii.) The marked current of the meter and shunt combined.

No. 37—1919.

( 21 )

(iv.) The pressure drop when carrying the marked current.

(v.) Where it is essential from considerations of accuracy for the shunt to be mounted in a special position this shall be clearly indicated on the shunt. 5

{b) The maximum observable temperature rise of any part of the shunt, above the temperature of the surrounding air, after carrying the marked current for two hours shall not exceed 75° C

{c) If the connections between the shunt and the meter 10 are not soldered, terminals shall be provided on both the meter and the shunt exclusively for these connections, and of such a nature that the resistance of the contacts shall be sufficiently constant to prevent the meter error being altered.

{d) The connections between the meter and the shunt shall 15 be marked with the serial number of the meter.

{e) If the marked current of the meter exceeds 100 amperes the pressure drop in the shunt and meter combined, when carrying marked current, shall not exceed 0*25 volt.

ALTERNATING CURRENT METERS.

20

Speed of Rotation.

53. The speed of the rotor shall not exceed 60 revolutions per minute at full load.

Diagram of Connections.

54. A diagram of connections in accordance with Clause 25 25 shall be attached to every meter (see Clause 14). In addition to giving the necessary information regarding connections the diagram shall show : —

{a) For meters carrying more than 100 amperes in the meter current circuits, the correct disposition of the conductors 30 carrying current to or from the meter, so that those errors may be avoided which result from the differences in the magnetic fields produced by placing such conductors in other than their correct positions.

{b) For two-element three-phase meters, the correct pliase 35 sequence of the .supply to the elements. In this case the diagram shall be shown in the form given in the figure, which shows the convention for connecting a two-element three-phase watt-hour meter to a three-phase network, in order to ensure- that each element shall have a definite relaiion to the direction ^o of phase rotation of the system.

No 37—1919.

( 22 )

WMITt OR YELLOW

SOURCL

OF SUPPLY

THE PRESSUnt KCACHCS

A MAXIMUM IN THE

PHAECC IM THE

FOLLOWINO SEQUENCE :-

1.Z.3

LOWER OR LEFT HAND ELEMENT OR TERMINALS.

UPPER OR RIOHI HAND ELEMENT OR TERMINALS

Variation of Frequency.

55. A variation of live per cent, above or below the marked frequency of the meter (see Clause 14) shall not cause a change in the rate of registration in respect of such variation of more than one per cent, at full load.

Variation of Power Factor.

56. A variation in the power factor of the load from unity to 0-5 (current lagging) when the meter (see Clause 14) is carrying its marked current at the marked pressure and frequency shall not cause a change in the rate of registration, in respect of such power factor variation, of more than two per cent. ; and the total error of the meter shall not exceed three per cent, when carrying any current between the marked current and one-quarter of the marked current at the marked pressure and frequency, and when the power factor of the load is 0-5.

10

15

No. 37—1919.

( 23 )

The requirements of this clause shall be fulfilled from the time the meter is first switched on to the main circuit until such circuit has been carrying its marked current for one hour.

Correct Registration of Unbalanced Loads.

57. Every polyphase meter (see Clause 74) shall comply with the requirements of this Specification, whether the load is balanced or unbalanced, that is to say, its electrical design shall not be based on a method of measurement which assumes that the three-phase load is symmetrical as regards current or pressure or phase angle.

No. 37—1919.

( 24 )

APPENDIX I. PRECAUTIONS NECESSARY IN THE ERECTION OF METERS.

Certain piccaiiiion.s should be observed wlien erecliiij^ meters, either for testing jjurposes or for permanent installation, otherwise the accuracy of the meter may be yreatly imjiaired, and the various ^

Clauses in the Specification dealinfj with accuracy may be rendered entirely ineffectual.

The following precautions are considered of special importance, hut they are not to be taken as constitulin>; complete instructions for the erection of meters. 10

(a) External Mas^/ieiic Fields. — Many of the precautions which are neces.sary arise from the fact that the strength of the magnetic field produced by the currents in the meter coils is not, in comparison with other magnetic fields which may exist in its neighbourhood, sufficiently great to render the readings of the meter independent of 15 the disturbing influence of such fields.

These disturbing influences may arise from any of the following causes, and must be taken account of in selecting positions for meters : —

(i.) A conductor carrying current in some circuit other 20 than that in which the meter is connected.

(ii.) A permanently magnetised iron framework used in the construction of a switchboard, or iron in the neighbourhood of the meter temporarily magnetised by conductors situated near it.

(iii. ) Other electrical apparatus carrying current and situated near the meter, especially circuit breakers

(iv.) Unless the instructions required by Clauses 50 and 54 are followed, both in erecting a meter for testing and when installing it permanently, errors may be caused by the magnetic field of the main conductors leading up to the meter itself or to its auxiliary apparatus.

Stray magnetic fields in the immediate neighboinhood of a switchboard are as a rule variable, and hence their influence on the registration of a meter is also variable. In some situations the only 35 means of ensuring accurate registration is to place the meters on a separate panel at a suitable distance from the switchboard proper.

{b) Level and Vibration. — The meter shoiikl be fixed level and in a position where vibration will not affect its running at light loads.

{c) Polarity. — The polarity marked on direct current meters {sec Clause 47) should be adhered to, since in some types the registration is incorrect with reversed polarity. The correct direction of rotation does not necessarily indicate that the polarity is correct.

25

30

40

No. 37—1919

( 25 )

{d) Con/ieciions to Large Meters. — The accuracy of large current meters or shunts may be seriously affected, unless the resistance of the main contacts is reduced to a minimum by these contacts being clean and well surfaced. Some meters can be put out of adjustment if the heavy connecting leads tend to twist or strain them. The 5 leads to and from the meter or shunt terminals should be supported independently of such terminals and connected in such a manner that they are not strained.

{e) Leads for Shunted Meters.— It is essential that only the leads supplied with the meter, and marked with the serial number of the 10 meter, as required by Clause 52 (^), should be used for connecting it with its shunt.

(/) Temperature. — The accurate registration of some types of direct current watt-hour meters requires that the auxiliary apparatus be subject to the same variations of air temperature as the 15 meter itself. This is more especially the case where an added resistance of copper in the pressure circuit is mounted in a separate box. Positions for erection, therefore, should be selected where no part of the apparatus is liable to be independendy heated by an extraneous source of heat or cooled by a draught. 20

{£) Phase Sequence. — Three-phase meters should be so con- nected to the supply that their elements have the proper relation to the direction of rotation of the system as shown in Clause 54. Provision is made in this clause for the necessary directions to be put on diagrams of connections affixed to meters. 25

{h) Additional Apparatus connected to Transformers. — The connection to the secondary windings of transformers, of trip coils, ammeters and similar additional apparatus in series with the meter coils is liable to affect the rate of registration of the meter. It is, therefore, essential that the meter should be tested and adjusted with all such apparatus connected in circuit, under similar conditions to those which will prevail in practice.

(/) Earthing of Secondary Circuits. — A meter for use on pressures exceeding 650 volts should have its case and one point on each of its low pressure windings connected to earth. 35

30

No. 37—1919.

( =6 )

APPENDIX II. Notes on the Testing of Meters.

Tliese notes are inleiule<l lo exi)Iain somtj of ihe conditions to he observed in the testing of meters under this Specification. They are not inteniied as exiiaustive instructions for testing, f)ut deal with a 5

numher of cases in which uncertainties might arise regarding tlie interpretation of a clause, or the correct tests to apply.

{a) Rate of Loss of Energy {Clause 20)). — The rate of loss of energy should be determined after both main and pressure; circuits have reached a steady state following on the application to them of marked 10 current and pressure respectively.

{l>) Alinimum Running Current [Clause 34). — In order to ascertain if the rotor continues to run steadily, the test should last long enough for the rotor of motor meters to make at least three complete revolutions. Any vibration of the meter during this te.st 15 should be avoided..

{c) Limits of Error {Clause 35). — Tests should only be made after the pressure circuit has been energised at marked pressure sufficiently long for the temperature to have reached a steady state as indicated by the constancy of the meter rate at any load. P'or 20 alternating current meters this period is often less than an hour. In some direct current meters it may be as long as six hours.

{d) Variation of Pressure {Clause 36). — 'I'he pressure of five per cent, above or below the marked pressure should be applied for a period long enough to ensure that the meter has reached a steady 25 state. The change in the rate of registration due to change of pressure is the difference between the speed of the meter under this condition, after a steady state has been reached, and the rate of registration at inarked pressure. When making these tests on direct current meters the pressure variations from the marked 30 pressure to five per cent, above or below the marked pressure should be gradual and the pressure circuit should not be broken during the period of test.

(1?) Variation due to Heati?ig by Main Current {Clause 38). — The time required to reach a steady state may in some meters be as 35 much as six hours.

(/) Excess Current and Pressure Tests {Clauses 30 and 40). — Before measurements are made to determine if there is any per- manent change of accuracy after the application of the excess load, the meter should be allowed to reach a normal temperature condition 4Q again.

{g) Non-Registratio7i with Pressure alo?te {Clause 41). — For motor meters the same precautions should lie observed as given in {b). For clock type meters a run of several hours is advisable.

No. 37—1919.

( -^7 )

{h) Shunis {Clauses 49 a fid 52). — To detect the presence in the shunt or in the meter main circuit of any thermal electro-motive force sufficient to affect the accuracy of the meter, the marked current should be maintained through the main circuit for a period of about one hour. If the rotor continues to revolve for more 5 than one complete revolution after switching off, the presence of a thermal E.M.F. is indicated. The above test to detect a thermal E.M.F. can only be used if the meter fulfils the requirements of Clauses 34 and 41.

(/) Variatioti of Freque7icy {Clause 55). — For tests under this 10 clause, the power factor should remain constant for any given determination of change of rate of registration with change of frequency. The power factor of the load at w^hich such deter- minations are made should be unity. The same precautions are to be observed as given in {c). 15

(/') Variation of Power Factor {Clause 56). — The same pre- cautions are to be observed as given in {c).

No. 37—1919.

( 28 )

APPENDIX III.

ILLUSTRATIONS OP TYPICAL ARRANGEMENTS OF METER REGISTERS.

The following illustrations show typical arrangements of Meter Registers which would comply with the requirements of Clause 33.

POINTER TYPES.

CLASS

CLASS III.

Illustrations of Classes IV. and V. would be exactly similar to those of Class III., except that the scale or opening marked " kw-h ' or " kw-h. per division " would be marked " 10 kw-h." or " to kw-h. per division" for Class IV., and "100 kw-h." or "100 kw-h. per division " for Class V.

No. 37 — 1919.

( 29 )

COUNTER TYPES.


KILOWATT-HOURS.	©0

CLASS I.

KILOWATT- HOURS.

KWH

0000

CLASS II.

KILOWATT-HOURS.

KWH

00000

CLASS III.

lUustralion.s of CIa.sses I\'. and V. would be exactly .similar to those of Clas.s III., except that the scale or opening marked "kw-h." or "kw-h. per division " would be marked " 10 kw-h." or " 10 kw-h. per division" for Class IV , and "100 kw-h." or "100 kw-h. per division " for Class V.

PRICE LIST

OF

BRITISH STANDARD SPECIFICATIONS AND REPORTS. JANUARY, 1919.

{This List cance/s all previous Li sis.)

Note. — Directly the necessary arrans[ements have been completed the Publicalioits of (he Association, with a few exceptions, will also be issued in French, Italian, Spanish and Portuguese. Both the English Editions and the Foreign Translations will be published in octavo form, and will be available at 1/— net per copy or its equivalent in Foreign moneys.

Report No.

1-1914. Rolled Sections fop Struc- tural Purposes, Lists of

2 1903. Tramway Rails and Fish- plates, Specification and Sections of

3-1903. Influence of Gauge Length and Section of Test Bar on the Percentage of Elongation, Report

on, by Professor W. C. Unwin, F.R.S

4-1903. Beams, Properties of (includ- ed in No. 6)

5-1905. Locomotives for Indian

Railways, First Report on (Super- seded by No. 50) ...

6-1904. Rolled Sections tor Struc- tural Purposes, Properties of ...

7-1910. Copper Conductors, Tables

uf

8-1904. Tramway Poles, Specifica- tion for Tubular

9-1909. Railway Rails, Specification and Sections of Bull Head

10-1904. Pipe Flanges, Tables of ...

11-1909. Railway Rails, Specification and Sections of Flat Bottom

12-1915. Portland Cement, Specifi- cation for...

13-1910. Steel for Shipbuilding,

.Specification for Structural...

14-1907. Steel for Marine Boilers,

Specification for Structural

15-1912. Steel for Bridges, etc., and (.eneral Building Construction,

Specification for Structural ...

16-1905. Telegraph Material, Speci-

lication for ... ...

17-1904. Electrical Machinery Re- port on (Superseded by No. 72-19T7)

18-1910. Tensile Test Pieces, Forms

of

19-1905. Temperature Experiments

on Field Coils of Klcctrical Machines, Report on ... ...

20 1913, Screw Threads, Report on

21-1909. Pipe Threads for Iron or Steel Pipes and Tubes, Report on ...

Net.	Post free.
1-	12
1/-	1/3

1-	12
Withd	awn.
Withd	rawn.
1-	13
1;-	13
1/-	1/2
1/-	13
1-	12
1/-	14
1-	12
1/-	12
1/-	1/2
1/-	12
1/-	1/5
Withdrawa
Gratis	-12
1/-	1/3
I-	12

1/- 1/2

22-1905. Insulating Materials, Re- port on the Effect of Tempera- ture on

23-1905. Trolley Groove and Wire,

Standards for ... ... ... .

24-1911. Railway Rolling Stock,

Specifications for Material used in the Construction of —

Part I. Locomotive, Carriage and Wagon Axles

,, II. Locomotive, Cariiage and Wagon Tyres

,, III. Laminated, Volute and Helical Springs and Steel for Laminated Springs ...

,, IV, Steel Forgings, Blooms and Castings

,, V. Copper Plates, Rods and Tubes and Brass Tubes...

,, VI. Steel Plates, Angles, etc., and Rivets for Locomo- tives, Carriages and Wagons

25-1906. Errors in Workmanship,

Report on ... ...

23-1907. Locomotives for Indian Railways, Second Report on (.Super- seded by No. 50)

27-1906. Limit Gauges for Running

Fits, Report on .Standard Systems of

28-1908. Nuts, Bolt Heads and Spanners, Report on

29-1909. Steel Forgings for Marine

Purposes, Specificaion for In.t;ot ...

30-1907. Steel Castings for Marine Purposes, Specification for

31-1910. Steel Conduits for Elec- trical Wirin?, Specification for ...

32-1907. Steel Bars for use in Auto- matic Machines. Specification for

33-1906. Carbon Filament Glow Lamps, Specification for

34-1913. Screw Threads, Tables of r.ritish Standard Whiiworth, British Standard Fine and British Standard Pipe Threads

Withdrawn. 1 - 12

1/-	12
1/-	12
1/-	1/2
1/-	1/2
1/-	1/2
1/-	1/2
Withd	awn
Withd	rawii
1/-	1'2
1/-	12
1/-	12
y-	12
1-	1'2
1'-	1/2
1-	1/2
Withd	rawn

LIST OF PUBLICATIONS -<:"«/««««-rt'.

Repuri '"■'

35-1907. Copper Alloy Barsfomsein Automatic Machines, Specification for 1- 13

36-1907. Electrical Machinery, Ke-

port on (Superseded by No. 72-1917) Withdrawn.

37-1919. Electricity Meters, Specifi-

c.ition for ... ... ■■. ... 1/- 12

38-1913. Limit Gauges for Screw Threads, Report on Standard Sys- tems ior Withdrawn.

39-1908. Screw Threads, Combined

Reports on W'itlidrawn.

40-1908. Cast Iron Low Pressure Heating Pipes, Specification for Spi:.;ot and Socket ... ... ... L- 1 2

41-1908. Cast Iron Flue or Smoke Pipes, Specification for Spigot and Socl<et 1- 1/2

42-1909, Steam Engines for Elec- trical Purposes, Report on Rccip- rocatini; ... .. ... ... ... 1- 12

43-1909. Boiler Tubes, Specification

for Charcoal Iron Lap-welded ... 1- 1,2

44-1909. Cast Iron Pipes for Hy- draulic Power, S])eciiication for ... 1- 12

45- 1917. Sparking Plugs (for Internal Combustion Engines), Report on Dimensions for ... ... ... ... 1 - 12

46-1909. Keys and Key ways. Speci- fication for 1- 1,2

47-1914. Steel Fishplates for Hull Head and Flat Hottom Railway Rails, Specification and Sections of ... 1/- 1/3

48-1909. Wrought Iron of Smithing equality for Shipbuilding (Grade I)), Specification for ... ... ... 1,'- 1/2

49-1909. Ammeters and Volt- meters, Specification for 1 - 1/2

50-1910. Locomotives for Indian

Railways, Third Report on (Super- Under seding N'os. 5 and 26) Revision.

51-1913. Wrought Iron for use in Railway Rolling Stock ("Best-York- shire" and Grades A, B and C), Specification for ... ... ... 1/- 12

52-1910. Lampholders and Caps. Under Specification for Bayonet Socket ... Revision,

53 1913. Boiler Tubes for Locomotive Boilers, SpecilKation for Cold Drawn WcKlless Steel 1'- 1'2

54-1911. Screw Threads, Nuts and Boll Heads for use in Automobile

Construction, Report on ... ... 1- 1/2

55-1911. Copper and Bronze Wire,

Report on Hard Drawn ... ... 1- 1/3

56-1911. Yield Point and Elastic

Limit, Definitions of Gratis. -/2

57-1911. Small Screws, Report on

Heads for 1/- 1,'2

58 1912. Cast Iron Soil Pipes, Speci- fication for Spigot and Socket .. 1,'- 12

59 1912. Cast Iron Waste and Ven- tilating Pipes (for other than Soil Purposes), Specification for Spigot

and Socket 1/- 12

60-1913. Tungsten Filament Glow

Lamps (Parts x and 2), Report on Kxperiments on 1/- 1/6

61-1913. Copper Tubes and their Screw Threads (primarily for domestic and similar work), Specifi- cation for 1'- 13

62-1913. Marine Boiler Stays, Screwing for

63-1913. Broken Stone and Chip- pings, Specification for Sizes of

64-1913. Fishbolts and Nuts for

Railway Rails, .Specification for

65-1914. Salt-Glazed Ware Pipes,

Specification for...

66-1914. Copper Alloy Three-Piece Unions (for Low and Medium Pressure Screwed Copper Tubes), Specification for ...

67-1914. Ceiling Roses, Specification for Two- and I'hree-Plate

68-1914. Steel Conductor Rails,

Method of Specifying the Resist- ance of

69-1915. Tungsten Filament Glow Lamps (Vacuum Type) for Auto- mobiles, Report on

70-1915. Pneumatic Tyre Rims for

Automobiles, Motor Cycles and Cycles, Report on

71-1917. Wheel Rims and Tyre Bands for Solid Rubber Tyres for Automobiles, Report on Dimen- sions of ... ... ...

72-1917. Electrical Machinery,

British Standardisation Rules for ...

73-1915. Wall Plugs and Sockets,

.Specification for .. 74- 1 9 1 7 . Charging Plug and Socket,

for Vehicles Propelled by ICIeclric Secondary Batteries, Specification for

75-1916. Steels for Automobiles, Specification for Wrought

76-1916. Tars, Pitches, Bitumens

and Asphalts when used for Road

Purposes, Report on Nomenclature of and Specifications for TaP and Pitch for Road Purposes

77-1916. Electrical Pressures for New Systems and Installations

(Low and Medium Pressures)

78 1917. Cast Iron Pipes and Special

Castings for Water, GaS and Sewage, Specification for ...

80 1917. Magnetos for Automobile

Purposes, Report on 1 )imensions i)f

82-1919. Starters for Electric Motors (Face Plate Type). Speci- fication for

83-Aprll, 1918, Dope and Protective Covering for Aircraft, Standard of

Reference for

84-1918. Screw Threads (British Standard Fine), B.S.F., and their Tolerances, Report on

85-April, 1918. Steel f. r Aircraft for Government Purchases in the United States of America, Speci- fications for

88-1919. Electric Cut-Outs (Low Pressure, Type O), Specifii .ition for

INTERIM REPORTS.

C.L. 2582. Ball Journal Bearings

for Autompbiles. Interim Repc^rt on Sizes of single Row

C.L. 3750. French Metric Screw Threads for Aircraft Purposes, Interim Report on

Net.	Post liee.
Gratis	-!2
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1-	1/2
1 -	1.3
1-	12
1-	1/2
1-	12
1-	12
1/-	1/2
1-	12
1-	12
1,'-	12
1-	12

1/- 12

Gratis - 2

1- 13

1/- 1/2

1/- 1,'2

L- 1/2

1/- 1/2

l/nder Revision.

1/- 12

Gratis -l\i

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